Dental-rubber-dam holder and cutter.



O. B. ELKINS & M. S. SMITH.

DENTAL RUBBER DAM HOLDER AND CUTTER.

APPLICATION FILED JULY 6. I9l6.

Pawnterl J une 19, 1917.

2 SHEETS-SHEET l.

0. B; ELKINS & M. 8. SMITH.

DENTAL RUBBER DAM HOLDER AND CUTTER.

APPLICATION FILED lULY 6.19M.-

Patented June 19, .1917.

2 SHEETS-SHEET 2.

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OTTO'B. ELKINS AND MARSHAL s. SMITH, 0F ABBE-VILLE, GEORGIA, ASSIGNORS 0F ONE-FOURTH TO NATHANIEL STATI-IAM, or ABBEVILLE, GEORGIA DENTAL-EUBBER-DAM HOLDER AND" CUTTER.

Specification of Letters Patent.

-Patentecl June 19, 1917.

To all whom it may concern:

Be it known that we, O'rro B. ELKINS and a full clear, and exact description'of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This-invention relates to improvements in devices for feeding and cutting lengths of material from a continuous strip or roll.

The object of the invention is to provide a simply constructed apparatus of this char acter in which a spring actuated feed roller is controlled by a reciprocatory member at the will of the operator.

Another object is to provide simple and eilicient means for severing the material so fed in any desired lengths. I

With the foregoing and other objects in View, which will appear as the description proceeds the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of. the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

In the accompanying drawings:

Figure 1 is a front elevation partly in section of this improved holder;

Fig. is a bottom plan view thereof;

Fig. 3 is an end elevation;

Fig. 4: is a transverse section taken on the line H of Fig. 1;

Fig. 5 is a similar view taken on the line 55 of Fig. 1;

Fig. 6 is a longitudinal section. thereof taken on the line 66 of Fig. 3

Fig. 7 is a similar view with the axle removed and looking. from the rear;

Fig. 8 is a detail perspective viewv of one of the toothed disks employed in the formation of the feeding wheel; and

Fig. 9 is a transverse section on the line 99 of Fig. 6.

In the embodiment illustrated, a cylindrical casing 1 is shown closed at one end and provided at its other end with a removable closure in the form of a cap 20. This cylinder has a slot 2 extending longitudinally througl'iout its length and through which the material to be fed is designed to pass.

Risingfrom the outer face of the upper wall of said slot is a sheath 3 for housing and guiding a movable knife blade 5 which operates through a slot 4: in one end of the sheath.

This blade is held yieldably in raised position by a coiled spring 5" secured at one end to said knife and at its other end to the sheath 3. A stationary knife 6 is secured to the outer face of the lower wall of the casing slot 2 and cooperates with the movable blade toform a shearing cut on the material fed out through said slot.

Arranged within the casing 1 on opposite sides of the slot 2 are r'otatably mounted feeding rollers 7 and 8, one of which is movable toward and away from the other for clamping the strip to be fed between them. The stationary roller 8 has a cog 9 shown arranged on its outer end, which is the end positioned at the cap carrying end of the casing and which is designed for a purpose to be described.

The outer end of the roller 7 has an arm or link'lO' engaged therewith and extending laterally therefrom through an aperture in the casing adjacent the slot .2. A cam lever 11 is engaged with the outer end of this link 10 and is operable to draw the link out through the casing and thereby move the roller 7 away from the roller 8 to permit the strip S to be fed between said rollers to be inserted.

A coiled spring 12 mounted on the link 10 between the roller 7 and the casing wall exerts its tension to force the roller 7 toward the roller 8 and hold it in yielding engagement therewith. wear plate 18- is engaged with the opposite faces of the casing around the aperture therein through which the link 10 passes. This plate extends through a slot in the casing and has a groove 14: on its outer face in which the lever 11 operates. This lever 11 is shown bifurcated with the link, 10 extending between the furcations thereof and piv'otally connected therewith. The cam portion 15 of the lever is held in yielding engagement with the wear plate 13 and said lever is providedwith a finger notch 16 although obviously any suitable gripping means may be provided to facilitate its operation. It will thus be seenthat by swinging the lever outward the roller 7 will be moved away from the roller 8 and when said lever is released the roller will be returned by the spring 12.

The casing 1 is also provided with alongitudinal slot 17 through which a reciprocatory member in the form of a stud 18 projects into the casing. This stud 18 which is designed for cooperation with a feed roller or ratchet wheel to be described and is carried by a block 18 mounted to slide in guides 19 arranged on opposite sides of said slot.

A roll carrying shaft or axle 21 is rotatablymounted in the casing 1, the closed end of said casing having a central bearing 22 to receive and support one end of the axle, the other, end thereof extending through and rotating in the cap 20. This axle 21 has a clutch member 23 near its outer end which cooperates with a clutch member 24 on the inner end of a sleeve 25 rotatably mounted on said axle beyond its clutch member 23, said axle being reduced beyond its clutch member 23 to receive said sleeve so that when the parts are assembled, the sleeve will be of the same diameter as the body portion of the axle.

This sleeve clutch member 24: is held in locking engagement with the axle clutch member 23 by means of a coiled spring 26 arranged on the outer end of the axle between a laterally extending flange 27 on the outer end of said sleeve and a nut 28 which is screwed on said axle end and by means of which the tension of the spring may be regulated.

A sleeve operating finger 29 projects laterally therefrom and is designed for rotating the sleeve to wind up a coiled spring 30 arranged in the cap 20. This spring 30 is secured at one end to said sleeve 25 and at its other end to the cap 20, and exerts its tension to rotate the axle in a direction opposite to the direction the sleeve is turned for feeding or unwinding the material from the roll carried by the axle. The interlocking faces of the clutch members 23 and 24 are in the form of ratchet teeth to provide for the turning of the sleeve 25 in one direction and to lock it against turning in the opposite direction so that the unwinding of the spring 30 will operate to rotate the axle, while the winding up thereof will not alfect any movement of the axle, which is owing to the fact that the sleeve is turned independently of the axle for winding up the spring.

A gear wheel 31 is fixed to the axle 21 in position to mesh with the cog on the roller 8 so that the rotation of the axle will operate also to turn the rollers 7 and 8. Longitudinally spaced annular disks 32 and 33 are fixed to the axle 21 and between which is disposed the roll of material to be carried by the casing and fed therefrom, said material being preferably a strip of rubber such as is usedfor rubber dams by dentists.

The inner disk 33 is provided on its outer face with teeth 3 1 which cooperate with similar teeth 35 on the opposed face of a wheel or disk 36 fixed to the shaft adjacent the disk 33 to form what may be termed a measuring or feeding wheel with which the reciprocatory stud 18 cooperates to lock and release the axle and permit it to rotate stepb-y-step underthe tension of the spring 30, whereby the strip S is intermittently fed through the slot 2 in the casing, the rollers 7 and 8 cooperating therewith to feed and guide the strip in its passage from the casing. The teeth on the disk alternate with those on disk 36 to permit the stud 18 to move between the teeth of the two members and engage first one and then the other on the reciprocation of the block 18 carrying the stud.

The disks 32 and 33 and the disk 36 have registering notches 37 to provide for the removal of the axle from the casing without interference by the stud 18.

In the use of this device, the cap 20 is first removed together with the axle mounted therein and the strip S in the form of a roll is arranged on said axle between the disks 32 and 33. The axle carrying the roll is then returned to the cylinder, care being taken that the notches in the disks 32 and 33 and disk 36 be alined with the stud 18 which will permit the axle to slide freely into the casing. The cap 20 is then replaced and the device is ready for use. The free end of the strip S is passed out of the slot 2 between the rollers 7 and 8 by first moving roller 7 away from roller 8 by means of the lever 11, as above described. After the end of the strip S has been fed out-between the rollers 7 and 8, any desired length thereof may be unrolled and fed out by recipcauses the stud 18 to engage first one tooth and then the other on the disk 33 and disk 36 respectively, thereby alternately releasing and locking the axle which turns forwardly under the action of the spring 30 and there by unwinds the strip S while the rollers 7 and 8 feed it out of the casing. After the desired length has been fed out, it may be severed by lowering knife 25 against the tension of its spring 5. When this knife is released it is raised to normal inoperative position by the springv5'.

I claim: 1

1. In a device of the class described, a casing, a roll supporting axle rotatably mounted in said casing, a spring connected to rotate said axle in one direction, and means reciprocable longitudinally relatively to said axle for locking said axle against rotation when said recipwcable means are moved in one direction and for releasing the axle when said means are moved in the opposite direction, whereby a step by step rotary movement may be imparted to said axle.

2. In a device of the class described, a casing, a roll supporting axle rotatably mounted in said casing, a spring connected to turn said axle in one direction, cooperating means carried by said axle and casing for normally holding said axle against turning by said spring, one of said means being reciprocable longitudinally relatively to said axle for imparting a step by step movement to said axle.

3. In a device of the class described a supporting structure, a spring actuated rollcarrying axle mounted to rotate therein, means for locking said axle from turning against the tension of its spring, and means reciprocatory in a plane parallel with the axis of said axle for intermittently releasing said locking means whereby a step-by-step rotation is imparted to said axle.

4. In a device of the class described, a supporting structure, a spring actuated rollcarrying axle mounted to rotate therein, means for locking said axle from turning against the tension of its spring, including a ratchet wheel fixed to said axle, and a stud carried by said supporting structure and movable to engage alternate teeth of said wheel whereby an intermittent rotary movement is imparted to said axle.

In a device of the class described, a supporting structure, a roll carrying axle mounted to rotate therein, a spring connected to turn said axle in one direction, a ratchet wheel fixed to said axle and having alternating teeth arranged out of peripheral alinement with each other, a pin normally engaging said ratchet wheel for holding said axle against turning by said spring, said pin being reciprocable longitudinally relatively to said axle for intermittently releasing said ratchet wheel for imparting a step by step movement to said axle.

6. In a device of the class described, a supporting structure, a roll-carrying axle mounted to rotate therein, a spring connected to turn said axle in one direction, a re ciprocatory stud mounted in said structure, a. wheel fixed to said axle and having alternating laterally spaced teeth arranged in the path of said stud whereby an intermittent rotary movement is imparted to said axle by said spring on the movement of said stud in opposite directions.

7. In a device of the class described, a supporting structure, an axle mounted to rotate therein and having a clutch member spaced from one end thereof, a sleeve mounted to rotate on said axle beyond said clutch member and having a clutch member for cooperation with said axle clutch member to lock said sleeve and axle against independent turning in one direction and per mit them to turn independently in the other direction, a coiled spring secured at one end to said sleeve and at its other end to said support, means for turning said sleeve to wind up said spring, means for holding said spring against unwinding, and means under the control of the operator for releasing said holding means.

8. A device of the class described including a casing, an axle mounted to rotate therein, a spiral spring connected to impart rotary motion in one direction to said axle, and clutch mechanism between said spring and axle to provide for the winding of the spring without rotating the axle.

9. A device of the class described including a casing having a longitudinal slot therein, feed rollers mounted to rotate in said casing, one of said rollers being movable laterally toward and away from the other, a lever connected to move said movable roller away from the other roller, and means for yieldingly urging said movable roller toward the other.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

OTTO B. ELKINS. MARSHAL s. SMITH.

\Vitnesses:

J. S. GRAHAM, C. L. GRAHAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

